 /*
  * $Header: /cvshome/build/org.osgi.framework/src/org/osgi/framework/BundleActivator.java,v 1.14 2007/02/21 16:49:05 hargrave Exp $
  *
  * Copyright (c) OSGi Alliance (2000, 2007). All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package org.osgi.framework;

 /**
  * Customizes the starting and stopping of a bundle.
  * <p>
  * <code>BundleActivator</code> is an interface that may be implemented when a
  * bundle is started or stopped. The Framework can create instances of a
  * bundle's <code>BundleActivator</code> as required. If an instance's
  * <code>BundleActivator.start</code> method executes successfully, it is
  * guaranteed that the same instance's <code>BundleActivator.stop</code>
  * method will be called when the bundle is to be stopped. The Framework must
  * not concurrently call a <code>BundleActivator</code> object.
  *
  * <p>
  * <code>BundleActivator</code> is specified through the
  * <code>Bundle-Activator</code> Manifest header. A bundle can only specify a
  * single <code>BundleActivator</code> in the Manifest file. Fragment bundles
  * must not have a <code>BundleActivator</code>. The form of the Manifest
  * header is:
  *
  * <p>
  * <code>Bundle-Activator: <i>class-name</i></code>
  *
  * <p>
  * where <code><i>class-name</i></code> is a fully qualified Java classname.
  * <p>
  * The specified <code>BundleActivator</code> class must have a public
  * constructor that takes no parameters so that a <code>BundleActivator</code>
  * object can be created by <code>Class.newInstance()</code>.
  *
  * @NotThreadSafe
  * @version $Revision: 1.14 $
  */

 public interface BundleActivator {
     /**
      * Called when this bundle is started so the Framework can perform the
      * bundle-specific activities necessary to start this bundle. This method
      * can be used to register services or to allocate any resources that this
      * bundle needs.
      *
      * <p>
      * This method must complete and return to its caller in a timely manner.
      *
      * @param context The execution context of the bundle being started.
      * @throws java.lang.Exception If this method throws an exception, this
      * bundle is marked as stopped and the Framework will remove this
      * bundle's listeners, unregister all services registered by this
      * bundle, and release all services used by this bundle.
      */
     public void start(BundleContext context) throws Exception ;

     /**
      * Called when this bundle is stopped so the Framework can perform the
      * bundle-specific activities necessary to stop the bundle. In general, this
      * method should undo the work that the <code>BundleActivator.start</code>
      * method started. There should be no active threads that were started by
      * this bundle when this bundle returns. A stopped bundle must not call any
      * Framework objects.
      *
      * <p>
      * This method must complete and return to its caller in a timely manner.
      *
      * @param context The execution context of the bundle being stopped.
      * @throws java.lang.Exception If this method throws an exception, the
      * bundle is still marked as stopped, and the Framework will remove
      * the bundle's listeners, unregister all services registered by the
      * bundle, and release all services used by the bundle.
      */
     public void stop(BundleContext context) throws Exception ;
 }

